Welding machine and welding method

Abstract

A fusion splicer (1) according to one embodiment is provided with: a stage (11) on which an optical fiber (F) is placed; a drive unit (14) that moves the stage (11); a microscope (15) that captures an image of the optical fiber (F) and outputs, for each pixel, the brightness of an image captured by the image; and a position recognition unit (20) that recognizes the position of the surface of the optical fiber on the basis of the brightness of each pixel output by the microscope (15). The drive unit (14) moves the optical fiber (F) by a certain distance each time. The distance is shorter than a pixel size of the pixel. The microscope (15) captures an image of the optical fiber (F) whenever the drive unit (14) moves the optical fiber (F) by a certain distance. The position recognition unit (20) recognizes the position of the surface of the optical fiber (F) moved by the drive unit (14) on the basis of a plurality of brightnesses of a plurality of images obtained by the microscope (15).

Description

Technical Field

[0001] The present disclosure relates to a fusion splicer and a fusion splicing method.

[0002] This application claims priority based on International Application PCT / JP2022 / 046279 filed on December 15, 2022, and incorporates the entire disclosure of the said international application. Background Art

[0003] A fiber optic fusion splicer is described in Patent Document 1. The fiber optic fusion splicer melts a pair of optical fibers while connecting the pair of optical fibers to each other. The fiber optic fusion splicer has a fiber feeding section that holds a plurality of optical fibers. The fiber feeding section moves the plurality of optical fibers along the longitudinal dimension of the optical fibers. The fiber optic fusion splicer includes a camera that continuously photographs the moving optical fibers and a control board. The control board has an image data processing section that processes the image data captured by the camera to identify the movement of the optical fibers. The image data processing section performs image data processing to identify the movement of the optical fibers based on the difference between a plurality of image data.

[0004] A fusion splicing method and a connecting device for optical fibers are described in Patent Document 2. The connecting device includes: a placement section on which the optical fibers are placed; a holder that holds a plurality of optical fibers; and a TV camera that photographs the plurality of optical fibers. The TV camera is provided for measuring the axial offset of the optical fibers.

[0005] A fusion splicing device for optical fibers is described in Patent Document 3. The fusion splicing device includes: a positioning table having a V-groove into which the optical fibers are inserted; a photographing camera that photographs the optical fibers from above the positioning table; and a core alignment fine movement mechanism that performs core alignment of the optical fibers. The photographing camera outputs the image of the optical fibers obtained by photographing as a photographing signal to an image processing device. The image processing device has: an arithmetic section that performs an arithmetic operation for core alignment of the optical fibers based on the photographing signal to generate a processing signal; and a control section that controls the operation of the core alignment fine movement mechanism according to the processing signal of the arithmetic section.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2005-189770

[0009] Patent Document 2: Japanese Unexamined Patent Application Publication No. 10-239553

[0010] Patent Document 3: Japanese Unexamined Patent Application Publication No. 5-164934 Summary of the Invention

[0011] The fusion splicer of the present disclosure includes: a stage for placing an optical fiber; a driving unit for moving the stage; a microscope for photographing the optical fiber and outputting the brightness of the image obtained by the photographing for each pixel; and a position recognition unit for recognizing the position of the surface of the optical fiber based on the brightness of each pixel output by the microscope. The driving unit moves the optical fiber a certain distance each time. This certain distance is shorter than the pixel size of the pixel. Whenever the driving unit moves the optical fiber a certain distance, the microscope photographs the optical fiber. The position recognition unit recognizes the position of the surface of the optical fiber after being moved by the driving unit based on the multiple brightnesses of the multiple images obtained by the microscope. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a perspective view showing the fusion splicer of the embodiment.

[0013] Figure 2 It is a perspective view showing the internal structure of the fusion splicer of the embodiment.

[0014] Figure 3 It is a perspective view showing the stage and the optical fiber of the fusion splicer of the embodiment.

[0015] Figure 4 It is a block diagram showing the functional configuration of the fusion splicer of the embodiment.

[0016] Figure 5 It is a diagram schematically showing an image of the optical fiber photographed by the microscope.

[0017] Figure 6 It is a diagram showing the position of the optical fiber in the image obtained by the photographing.

[0018] Figure 7 It is a diagram showing an image of the optical fiber obtained by the photographing.

[0019] Figure 8 It is a flowchart showing an example of the steps of the fusion splicing method of the embodiment.

[0020] Figure 9 It is a diagram for explaining the process of moving the optical fiber, photographing the optical fiber, and recognizing the position of the optical fiber.

[0021] Figure 10 It is a diagram for explaining the process of moving the optical fiber, photographing the optical fiber, and recognizing the position of the optical fiber in a modified example.

[0022] Figure 11 It is for explaining with Figure 10 different modified examples of the process of moving the optical fiber, photographing the optical fiber, and recognizing the position of the optical fiber.

[0023] Figure 12 It is for explaining with Figure 9 andFigure 10 A diagram for explaining the processes of movement of an optical fiber, photographing of the optical fiber, and identification of the position of the optical fiber in different modification examples.

[0024] Figure 13 A diagram for explaining the processes of movement of an optical fiber, photographing of the optical fiber, and identification of the position of the optical fiber in further modification examples.

[0025] Figure 14 It shows the Figure 13 position of the surface of the optical fiber measured through the process.

[0026] Figure 15 A diagram for explaining the processes of movement of an optical fiber, photographing of the optical fiber, and identification of the position of the optical fiber in further modification examples.

[0027] Figure 16 It shows the Figure 15 position of the surface of the optical fiber measured through the process. DETAILED DESCRIPTION

[0028] Furthermore, when the resolution of the microscope for photographing the optical fiber is low, the image may become rough. In particular, in a fusion splicer for fusing multi-core optical fibers, since multiple optical fibers are photographed, the magnification of the microscope may be low magnification. In this case, the resolution of the microscope tends to be low. As a result, the image of the optical fiber is rough, and sometimes the position of the surface of the optical fiber cannot be accurately identified. For example, when the position of the end face of the optical fiber to be fused cannot be accurately identified, connection loss of the optical fiber may occur.

[0029] An object of the present disclosure is to provide a fusion splicer capable of accurately identifying the position of the surface of an optical fiber.

[0030] [Description of Embodiments of the Present Disclosure]

[0031] First, embodiments of the present disclosure will be listed and described. A fusion splicer (1) according to one embodiment includes: a stage for placing an optical fiber; a driving unit for moving the stage; a microscope for photographing the optical fiber and outputting the brightness of the image obtained by photographing for each pixel; and a position identification unit for identifying the position of the surface of the optical fiber based on the brightness of each pixel output by the microscope. The driving unit moves the optical fiber a certain distance each time. This certain distance is shorter than the pixel size of the pixel. Each time the driving unit moves the optical fiber a certain distance, the microscope photographs the optical fiber. The position identification unit identifies the position of the surface of the optical fiber after being moved by the driving unit based on the multiple brightnesses of the multiple images obtained by the microscope.

[0032] In this fusion splicer, a stage on which an optical fiber is placed is moved by a driving unit, and the surface of the moving optical fiber is photographed by a microscope. The microscope outputs the brightness of the image obtained by photographing for each pixel. A position recognition unit recognizes the position of the optical fiber based on the brightness of each pixel of this image. The driving unit moves the optical fiber each time by a certain distance shorter than the pixel size of a pixel. Whenever the optical fiber is moved by the certain distance, the microscope photographs the optical fiber. Then, the position recognition unit recognizes the position of the surface of the moved optical fiber based on the brightness of multiple images. Therefore, an image is obtained whenever the optical fiber is moved by a certain distance shorter than the pixel size, and the position of the surface of the optical fiber is recognized based on the brightness of multiple images. Thus, the position of the surface of the optical fiber can be recognized with high precision. Even when the resolution of the microscope is low and the pixels of the image are rough, by photographing the image whenever the optical fiber is moved by a certain distance shorter than the pixel size, the position of the surface of the optical fiber can be accurately recognized from the multiple images obtained from the result of this photographing.

[0033] (2) In the above (1), it may also be that the position recognition unit recognizes the position of the surface of the optical fiber in the image among the multiple images where the position of the surface of the optical fiber is closest to one side of the pixel as the reference position. In this case, the position recognition unit can more accurately recognize the position of the surface of the moved optical fiber by recognizing how many times the driving unit has moved the optical fiber by the certain distance from the reference position.

[0034] (3) In the above (2), it may also be that the position recognition unit recognizes the position of the optical fiber in the image among the multiple images where the brightness difference between two pixels arranged along the moving direction of the optical fiber is the largest as the reference position. In this case, the position recognition unit can easily recognize the reference position based on the brightness difference between two pixels arranged along the moving direction.

[0035] (4) In the above (2) or (3), it may also be that the position recognition unit stores the moving distance of the optical fiber from the reference position, or it may be that the position recognition unit adds the moving distance of the optical fiber from the reference position to the reference position to recognize the position of the surface.

[0036] (5) In the above (4), it may also be that the position recognition unit stores how many times the optical fiber has been moved by the certain distance from the reference position, or it may be that the position recognition unit adds the product of the number of times the optical fiber has been moved from the reference position and the certain distance as the moving distance to the reference position to recognize the position of the surface.

[0037] (6) In any one of the above (1) to (5), it may also be that the position recognition unit recognizes the position of the optical fiber in the image in which the brightness difference between two pixels arranged along the moving direction is the largest among the multiple images for each pixel arranged in the direction orthogonal to the moving direction of the optical fiber. In this case, since the position of the optical fiber is recognized for each pixel arranged in the direction orthogonal to the moving direction, the position of the surface can be measured in detail even if the shape of the surface of the optical fiber is complex.

[0038] (7) In the above (6), it may also be that the position recognition unit stores how many times the optical fiber has moved a certain distance, or it may be that the position recognition unit recognizes the position of the surface by subtracting the product of the number of times the optical fiber has moved and the certain distance from the position of the optical fiber in the image with the largest brightness difference. In this case, the position of the surface of the optical fiber before movement can be measured.

[0039] (8) In the above (6) or (7), it may also be that the position recognition unit recognizes the position of the surface for each pixel arranged in the direction orthogonal to the moving direction. In this case, the position of the surface of the optical fiber before movement can be measured in more detail.

[0040] (9) In any one of the above (1) to (8), it may also be that the driving unit moves the optical fiber along the long dimension direction of the optical fiber.

[0041] (10) In any one of the above (1) to (8), it may also be that the driving unit moves the optical fiber along the direction orthogonal to the long dimension direction of the optical fiber.

[0042] (11) In any one of the above (1) to (10), it may also be that the above-mentioned certain distance is less than or equal to half of the pixel size. In this case, by taking images of the optical fiber every time it moves a certain distance less than or equal to 1 / 2 of the pixel size, the position of the surface of the optical fiber can be more accurately recognized from multiple images.

[0043] (12) In any one of the above (1) to (11), it may also be that the above-mentioned surface is the end face of the optical fiber at one end in the long dimension direction of the optical fiber. In this case, the position of the end face of the optical fiber can be accurately recognized.

[0044] (13) In any one of the above (1) to (11), it may also be that the above-mentioned surface is the side face of the optical fiber extending along the long dimension direction of the optical fiber. In this case, the position of the side face of the optical fiber can be accurately recognized.

[0045] (14) In any one of the above (1) to (13), it may also be that the microscope has: an imaging element that images the optical fiber; and an image processing unit that processes the image of the optical fiber captured by the imaging element. It may also be that the image processing unit outputs the brightness of the image for each pixel.

[0046] (15) In the above (14), it is also possible that the image processing unit calculates the brightness difference between two pixels arranged along the moving direction of the optical fiber, or it is also possible that the position recognition unit stores the brightness difference calculated by the image processing unit.

[0047] (16) In any one of the above (1) to (15), it is also possible that the fusion splicer is a multi-core fusion splicer that fuses multiple optical fibers together.

[0048] (17) In any one of the above (1) to (16), it is also possible that the position recognition unit stores the image captured by the microscope and recognizes the position of the optical fiber based on the brightness of each pixel output.

[0049] (18) In any one of the above (1) to (17), it is also possible that the position recognition unit recognizes the position of the plane as the position of the pixels between the pixel with the highest brightness and the pixel with the lowest brightness among multiple pixels.

[0050] The fusion splicing method of one embodiment (19) includes the following steps: moving the stage on which the optical fiber is placed; photographing the optical fiber; outputting the brightness of the image obtained through the photographing step for each pixel; and recognizing the position of the plane of the optical fiber based on the brightness of each pixel. In the moving step, the optical fiber is moved a certain distance each time. The certain distance is shorter than the pixel size of the pixel. In the photographing step, the optical fiber is photographed each time the optical fiber moves a certain distance. In the position recognition step, the position of the plane of the moved optical fiber is recognized based on the multiple brightnesses of multiple images.

[0051] In this fusion splicing method, similar to the above fusion splicer, the plane of the moving optical fiber is photographed, and the brightness of the image obtained through the photographing is output for each pixel. In the position recognition step, the position of the optical fiber is recognized based on the brightness of each pixel of this image. In this position recognition, the position of the plane of the moved optical fiber is recognized based on the multiple brightnesses of multiple images. Therefore, similar to the above fusion splicer, an image is obtained each time the optical fiber moves a certain distance shorter than the pixel size, and by recognizing the position of the plane of the optical fiber based on the multiple brightnesses of multiple images, the position of the plane of the optical fiber can be recognized with high precision. As a result, even when the resolution of the microscope is low and the pixels of the image are rough, by photographing the image each time it moves a certain distance, the position of the plane of the optical fiber can be accurately recognized from the multiple images obtained from the result of this photographing.

[0052] [Details of the Embodiment of the Invention of the Present Application]

[0053] Specific examples of the fusion splicer and the fusion splicing method according to the embodiments of the present disclosure will be described. In the description of the drawings, the same or corresponding elements are denoted by the same reference numerals, and repeated descriptions are appropriately omitted. In the drawings, for ease of understanding, a part may be simplified or exaggeratedly depicted, and the dimensional ratios and the like are not limited to those described in the drawings.

[0054] Figure 1 FIG. 4 is a perspective view showing the fusion splicer 1 as a specific example. The fusion splicer 1 has a box-shaped housing 2 and a wind shield 6 located above the housing 2. Figure 2 FIG. 5 is a perspective view showing a state where the wind shield 6 is opened. As shown in FIGS. Figure 1 and Figure 2 10, the fusion splicer 1 has a fusion splicing part 3 for fusing optical fibers with each other. The fusion splicer 1 has a monitor 5 for displaying the state of fusion splicing of optical fibers with each other photographed by a microscope 15 (refer to Figure 4 ). Further, the fusion splicer 1 has: a heater 4 for heating and shrinking an optical fiber reinforcing sleeve covering a connection part of the optical fibers fused in the fusion splicing part 3; a power switch 7 for switching on / off the power of the fusion splicer 1; and a connection start switch 8 for performing fusion splicing of optical fibers.

[0055] The fusion splicing part 3 includes, for example, a pair of optical fiber positioning parts 3a, a pair of electrode rods 3b for discharging, and a pair of optical fiber holders 3c. Each optical fiber to be fused is held by the optical fiber holder 3c. The optical fiber positioning part 3a is disposed between the pair of optical fiber holders 3c and positions the end faces of the optical fibers fixed to the respective optical fiber holders 3c. The "end face" means the face of the optical fiber located at one end in the long dimension direction of the optical fiber. The pair of electrode rods 3b are disposed between the pair of optical fiber positioning parts 3a. The electrode rods 3b are electrodes for fusing the end faces of the optical fibers with each other by arc discharge. The electrode rods 3b and the optical fiber holders 3c are arranged along the Z-axis direction. The Z-axis direction is the direction in which the plurality of optical fibers to be fused extend.

[0056] The wind shield 6 is connected to the housing 2 so as to cover the fusion splicing part 3 in an openable and closable manner. The power switch 7 is a button for switching on / off the power of the fusion splicer 1 according to the operation of the user of the fusion splicer 1. The connection start switch 8 is a button for starting the operation of fusing optical fibers with each other according to the operation of the user.

[0057] Figure 3 FIG. 22 is a perspective view schematically showing the detailed structure of the fusion splicing part 3. As shown in Figure 3 FIG. 24, the fusion splicer 1 has a stage 11 on which a plurality of optical fibers F to be fused are placed. In the present embodiment, the fusion splicer 1 is a multi-core fusion splicer for fusing a plurality of optical fibers F at once. The fusion splicer 1 has a pair of stages 11 arranged along the Z-axis direction.

[0058] The stage 11 has a main surface 12 for placing a plurality of optical fibers F, and a plurality of V-grooves 13 that are recessed in the main surface 12 and into which the optical fibers F enter. In the stage 11, the plurality of V-grooves 13 are arranged along the X-axis direction that intersects the Z-axis direction. The X-axis direction is the in-plane direction of the main surface 12, for example, a direction orthogonal to the Z-axis direction. Each V-groove 13 is recessed from the main surface 12 in the Y-axis direction that intersects both the X-axis direction and the Z-axis direction. The Y-axis direction is, for example, a direction orthogonal to both the X-axis direction and the Z-axis direction. The plurality of optical fibers F inserted into the respective V-grooves 13 are arranged along the X-axis direction on the main surface 12. A pair of electrode rods 3b are respectively disposed on both sides in the X-axis direction when viewed from the plurality of optical fibers F.

[0059] The fusion splicer 1 has a drive unit 14 that moves the stage 11. The drive unit 14 moves a pair of stages 11, for example. The drive unit 14 moves the optical fiber F placed on the stage 11 along the Z-axis direction, for example. In this case, the Z-axis direction is the moving direction of the optical fiber. The drive unit 14 adjusts the position of the end face F1 of the optical fiber F by moving the stage 11 along the Z-axis direction. The drive unit 14 adjusts the position of the optical fiber F in the Z-axis direction such that the distance from the imaginary straight line L connecting the pair of electrode rods 3b to the end face F1 is a specified distance. By performing this adjustment on the pair of optical fibers F arranged along the Z-axis direction by the drive unit 14, the fusion splicing of the optical fiber F based on the pair of electrode rods 3b can be appropriately performed.

[0060] The drive unit 14 is, for example, a stepping motor. In this case, the drive unit 14 is driven according to the applied pulse voltage. By the drive of the drive unit 14, the stage 11 moves along the Z-axis direction. For example, the drive unit 14 finely moves the optical fiber F placed on the stage 11 in order to finely adjust the position of the end face F1 of the optical fiber F. "Fine movement" means moving a distance shorter than the pixel size of the image captured by the microscope 15 described later. In addition, the "pixel size" mentioned here refers to the length measured along the moving direction of the optical fiber F. The drive unit 14 moves the optical fiber F a certain distance each time it makes a fine movement. The "certain distance" represents, for example, the amount of movement of the optical fiber F per pulse of the drive unit 14. For example, the "certain distance" is 1 μm or more and less than 10 μm. As an example, the "certain distance" is 2 μm.

[0061] Figure 4 is a block diagram showing the functions of the microscope 15 and the position recognition unit 20. Figure 5 is a diagram showing the image captured by the microscope 15. As Figure 4 and Figure 5As shown in the figure, the fusion splicer 1 includes: a microscope 15 that captures an image of the optical fiber F; and a position recognition unit 20 that recognizes the position of the end face F1 of the optical fiber F from the image of the optical fiber F captured by the microscope 15. The microscope 15 captures images of a plurality of optical fibers F respectively placed on a pair of stages 11. The microscope 15 is, for example, a CCD camera (Charge-Coupled Device Camera) or a CMOS camera (Complementary Metal Oxide Semiconductor Camera).

[0062] The microscope 15, for example, includes an imaging element 16 and an image processing unit 17. The imaging element 16 captures an image of the optical fiber F, and the image processing unit 17 processes the image of the optical fiber F captured by the imaging element 16. The image processing unit 17 outputs the brightness of the image for each pixel. The pixel size of the image captured by the imaging element 16 is larger than the above-mentioned certain distance. For example, the pixel size of the image captured by the imaging element 16 is greater than or equal to twice the above-mentioned certain distance. Since the fusion splicer 1 is a multi-core fusion splicer and needs to capture images of a plurality of optical fibers F arranged along the X-axis direction, the pixel size is set to a relatively large value. As an example, the pixel size is 10 μm.

[0063] As the position recognition unit 20, for example, a CPU (Central Processing Unit) composed of one or more integrated circuits (ICs: Integrated Circuits) is used. For example, the position recognition unit 20 stores the image captured by the imaging element 16. The position recognition unit 20 recognizes the position of the optical fiber F based on the brightness of each pixel output by the image processing unit 17.

[0064] Figure 6 It is a diagram showing the end face F1 of the optical fiber F in the captured image. Figure 7 It is a diagram showing the image of the captured optical fiber F. As Figure 6 and Figure 7 shown, when the pixel size of this image is large, it is possible that the actual position P of the end face F1 in the Z-axis direction is blurred, so that the position recognition unit 20 cannot recognize the accurate position of the end face F1. More specifically, it is possible that the position recognition unit 20 can recognize that the end face F1 is located in the blurred pixel X part of this image, but cannot recognize which position in the pixel X the end face F1 is located.

[0065] On the other hand, the driving unit 14 finely adjusts the position of the end face F1 in the Z-axis direction in order to appropriately perform the fusion splicing of the optical fiber F. However, when the position recognition unit 20 cannot recognize the accurate position of the end face F1 as described above, it may occur that the fusion splicing cannot be appropriately performed because the end face F1 may not be in the appropriate position. In this case, connection failure or the like may occur. In contrast, in the fusion splicer 1 and the fusion splicing method of the present embodiment, the position recognition unit 20 can recognize the accurate position of the end face F1. Hereinafter, an example of the steps of the fusion splicing method will be described.

[0066] Figure 8 It is a flowchart showing an example of the steps of the fusion splicing method of the present embodiment. Figure 9 It is a diagram showing an image captured by the microscope 15. In this fusion splicing method, a pair of optical fibers F to be fusion spliced are respectively arranged on a pair of stages 11 with a pair of end faces F1 facing each other (step of arranging the optical fibers, step S1). At this time, the optical fibers F are inserted into the respective V-grooves 13 of the stages 11, and the optical fibers F are arranged on each stage 11 in such a manner that a plurality of optical fibers F are arranged along the X-axis direction.

[0067] Next, the microscope 15 captures an image of the optical fiber F (step of capturing an image of the optical fiber, step S2). At this time, an image M1 of the optical fiber F is obtained by the imaging element 16. Then, the image processing unit 17 outputs the brightness of the image M1 for each pixel X1. For example, the brightness of each pixel X1 of the image M1 output by the image processing unit 17 is output to the position recognition unit 20. In this case, the position recognition unit 20 recognizes the position of the end face F1 based on the brightness of each pixel X1 of the image M1. As a specific example, the position recognition unit 20 recognizes the position of the pixel X13 between the pixel X11 with the highest brightness and the pixel X12 with the lowest brightness among the plurality of pixels X1 as the position of the end face F1.

[0068] Next, the driving unit 14 moves the stage 11 on which the optical fiber F is placed (step of moving the stage). For example, the driving unit 14 fixes one of the two stages 11 and moves the unfixed stage 11 in the Z-axis direction. At this time, the driving unit 14 finely moves the optical fiber F to move the optical fiber F a certain distance in the Z-axis direction (step S3). After that, the microscope 15 captures an image of the optical fiber F (step of capturing an image of the optical fiber, step S4). At this time, an image M2 of the optical fiber F is obtained by the imaging element 16.

[0069] The image processing unit 17 outputs the brightness of the image M2 for each pixel X1 and calculates the brightness difference. For example, the position recognition unit 20 stores the brightness difference calculated by the image processing unit 17. The image processing unit 17 calculates, for example, the brightness difference between two pixels X1 arranged along the Z-axis direction (the process, step S5 of calculating the brightness difference). For example, the image processing unit 17 calculates the difference between the brightness of the pixel X11 and the brightness of the pixel X13 as the brightness difference. The image processing unit 17 outputs the brightness of each pixel X1 of the image M2 to the position recognition unit 20.

[0070] The position recognition unit 20 determines, for example, whether the optical fiber F has reached the fusion position (the process, step S6 of determining whether the optical fiber has reached the fusion position). The "fusion position" is, for example, the position of the end face F1 where the optical fiber F can be fused by the electrode bar 3b.

[0071] When the position recognition unit 20 determines in step S6 that the optical fiber F has reached the fusion position, it moves to step S7. On the other hand, when the position recognition unit 20 determines in step S6 that the optical fiber F has not reached the fusion position, it returns to step S3. Then, the drive unit 14 finely moves the optical fiber F, the microscope 15 captures an image M3 of the optical fiber F, and then the image processing unit 17 performs the above-described calculation of the brightness difference on the image M3.

[0072] For example, when the position recognition unit 20 determines that the optical fiber F has not reached the fusion position, the drive unit 14 finely moves the optical fiber F again, the microscope 15 captures an image M4 of the optical fiber F, and then the image processing unit 17 performs the above-described calculation of the brightness difference on the image M4. For example, after obtaining an image M5 in the same manner as above, the image processing unit 17 performs the above-described calculation of the brightness difference on the image M5. Then, when the position recognition unit 20 determines that the optical fiber F has reached the fusion position (yes in step S6), the position recognition unit 20 performs the recognition of the reference position (the process, step S7 of recognizing the reference position).

[0073] In step S7, the position recognition unit 20 recognizes the position of the end face F1 of the optical fiber F in the captured images M1, M2, M3, M4, and M5 that is closest to one side of the pixel X1 in the image M3 as the reference position Y. More specifically, the position recognition unit 20 recognizes the position of the end face F1 of the optical fiber F in the image M3 with the largest brightness difference between two pixels X11 and X13 arranged along the Z-axis direction as the reference position Y.

[0074] As a specific example, when comparing image M1 and image M2 with image M3, pixel X13 is blurred. That is, the brightness difference of pixel X13 relative to the brightness of pixel X11 is small. Therefore, at the time points when images M1 and M2 are captured, the position recognition unit 20 cannot accurately recognize the position of the end face F1. In contrast, when image M3 is captured, compared with images M1 and M2, pixel X13 is clear. That is, the brightness difference of pixel X13 relative to the brightness of pixel X11 is large. Therefore, at the time point when image M3 is captured, the position recognition unit 20 can accurately recognize the position of the end face F1. The position on one side of pixel X1 corresponds one-to-one with the actual position. Thus, the greater the brightness difference of pixel X13 relative to the brightness of pixel X11, and the closer the position of the captured end face F1 is to the position on one side of pixel X1, the more accurately the position recognition unit 20 can recognize the position of the end face F1.

[0075] After the position recognition unit 20 recognizes the reference position Y, it recognizes the position of the end face F1 of the optical fiber F (the process of recognizing the position of the face of the optical fiber, step S8). The position recognition unit 20 stores how many times the optical fiber F has moved a certain distance from the reference position Y. In Figure 9 this example, the optical fiber F has moved twice from the reference position Y. Therefore, the position recognition unit 20 can accurately recognize the position of the end face F1 at the time point when image M5 is captured by adding the product of the number of times the optical fiber F has moved from the reference position Y and the certain distance as the moving distance to the reference position Y. In addition, it can also be that the position recognition unit 20 stores the moving distance of the optical fiber F from the reference position Y, or the position recognition unit 20 adds the moving distance of the optical fiber F from the reference position Y to the reference position Y to recognize the position of the end face F1.

[0076] Next, the effects obtained by the fusion splicer 1 and the fusion splicing method of the present embodiment will be described. In the fusion splicer 1 and the fusion splicing method of the present embodiment, the stage 11 on which the optical fiber F is placed is moved by the drive unit 14, and the surface of the moving optical fiber F is photographed by the microscope 15. The microscope 15 outputs the brightness of the images M1, M2, M3, M4, M5 obtained by photographing for each pixel X1. The position recognition unit 20 recognizes the position of the optical fiber F based on the brightness of each pixel X1 of the images M1, M2, M3, M4, M5. The drive unit 14 moves the optical fiber F each time by a certain distance shorter than the pixel size of the pixel X1. Whenever the optical fiber F moves a certain distance, the microscope 15 photographs the optical fiber F. Then, the position recognition unit 20 recognizes the position of the surface of the moved optical fiber F based on the multiple brightnesses of the images M1, M2, M3, M4, M5. Therefore, by moving the optical fiber F by a certain distance shorter than the pixel size and photographing the optical fiber F to obtain the images M1, M2, M3, M4, M5, and recognizing the position of the surface of the optical fiber F based on the multiple brightnesses of the images M1, M2, M3, M4, M5, the position of the surface of the optical fiber F can be recognized with high precision. Even when the resolution of the microscope 15 is low and the pixels X1 of the images M1, M2, M3, M4, M5 are rough, by photographing the images M1, M2, M3, M4, M5 each time when moving a certain distance shorter than the pixel size, the position of the surface of the optical fiber F can be accurately recognized from the images M1, M2, M3, M4, M5.

[0077] As described above, it may also be that the position recognition unit 20 recognizes the position of the surface of the optical fiber F in the images M1, M2, M3, M4, M5 that is closest to one side of the pixel X1 in the image M3 as the reference position Y. In this case, the position recognition unit 20 can more accurately recognize the position of the surface of the moved optical fiber F by recognizing how many times the drive unit 14 has moved the optical fiber F by a certain distance from the reference position Y.

[0078] As described above, it may also be that the position recognition unit 20 recognizes the position of the optical fiber F in the image M3 with the largest brightness difference between the two pixels X11 and X13 arranged along the Z-axis direction in the images M1, M2, M3, M4, M5 as the reference position Y. In this case, the position recognition unit 20 can easily recognize the reference position Y based on the brightness difference between the pixels X11 and X13 arranged along the Z-axis direction.

[0079] It may also be that the above-mentioned certain distance is less than or equal to one-half of the pixel size. In this case, by photographing the images M1, M2, M3, M4, M5 of the optical fiber F each time when moving a certain distance of 1 / 2 or less of the pixel size, the position of the surface of the optical fiber F can be accurately recognized from the images M1, M2, M3, M4, M5.

[0080] Alternatively, the surface described above is the end face F1 at one end in the long dimension direction of the optical fiber F. In this case, the position of the end face F1 of the optical fiber F can be accurately identified. As a result, fusion of a pair of end faces F1 arranged along the Z-axis direction can be appropriately performed, and thus the occurrence of poor contact can be suppressed.

[0081] Next, various modified examples of the fusion splicer and the fusion splicing method of the present disclosure will be described. A part of the fusion splicer and the fusion splicing method of the modified example is the same as a part of the fusion splicer and the fusion splicing method of the above-described embodiment. Accordingly, the same reference numerals are given below and descriptions that are the same as those already presented are appropriately omitted.

[0082] Figure 10 FIG. is for explaining a fusion splicing method of a modified example. In the above-described embodiment, an example in which the drive unit 14 fixes one of the two stages 11 and moves the unfixed stage 11 in the Z-axis direction has been described. In contrast, in the fusion splicing method of the modified example, each stage 11 is moved a certain distance each time so that a pair of optical fibers F approach each other.

[0083] Then, in the same manner as in the above-described embodiment, each time the optical fiber F is moved a certain distance, the optical fiber F is photographed. Each time a pair of optical fibers F are moved a certain distance so as to approach each other, the microscope 15 photographs the pair of optical fibers F. The position recognition unit 20 recognizes the positions of the respective end faces F1 of the moved optical fibers F based on the brightness of the image M6. In this case, the position recognition unit 20 can recognize the distance between the pair of end faces F1. In addition, when the imaginary straight line L connecting the pair of electrode rods 3b extends along one side of the pixel X2 of the image M6, the distance of each end face F1 from the imaginary straight line L can be calculated. Therefore, fusion of the pair of optical fibers F can be performed more appropriately.

[0084] Figure 11 is for explaining Figure 10 a fusion splicing method of a different modified example. Figure 11 Corresponding to the above Figure 9 , the moving direction of the optical fiber F is different from Figure 9 . In the modified example shown in Figure 11 , for example, in order to align the optical fiber F, the drive unit 14 moves the optical fiber F a certain distance in the X-axis direction. An image of the side face F2 of the optical fiber F is obtained by photographing the optical fiber F with the microscope 15.

[0085] While moving the optical fiber F a certain distance along the X-axis direction by the same method as for obtaining the above-described images M1, M2, M3, M4, and M5, the position recognition unit 20 acquires images M11, M12, M13, M14, and M15. Then, when the position recognition unit 20 recognizes that the optical fiber F has reached the adjustable core position, the position recognition unit 20 recognizes the reference position. At this time, the position recognition unit 20 recognizes the position of the side surface F2 of the optical fiber F in the image M13, which is the closest to one side of the pixel X3 among the images M11, M12, M13, M14, and M15, as the reference position Z.

[0086] More specifically, the position recognition unit 20 recognizes the position of the side surface F2 of the optical fiber F in the image M13, where the brightness difference between the two pixels X14 and X15 arranged along the X-axis direction is the largest, as the reference position Z. After the position recognition unit 20 recognizes the reference position Z, it recognizes the position of the side surface F2 of the optical fiber F at the time point when the image M15 is captured. Specifically, the position recognition unit 20 can accurately recognize the position of the side surface F2 at the time point when the image M15 is captured by adding the product of the number of times the optical fiber F has moved from the reference position Z and a certain distance to the reference position Z.

[0087] Above, in Figure 11 the example, the driving unit 14 moves the optical fiber F along the X-axis direction orthogonal to the long dimension direction of the optical fiber F. Then, the surface of the optical fiber F to be recognized is the side surface F2 of the optical fiber F extending along the long dimension direction of the optical fiber F. In Figure 11 the example, the position of the side surface F2 of the optical fiber F can be accurately recognized.

[0088] Figure 12 is a diagram for explaining a fusion method of a modified example different from Figure 10 and Figure 11 . In Figure 12 the example, the driving unit 14 moves a pair of optical fibers F arranged along the Z-axis direction respectively along the X-axis direction. Then, whenever each optical fiber F moves a certain distance along the X-axis direction, the microscope 15 captures images of the pair of optical fibers F. The position recognition unit 20 recognizes the positions of the respective side surfaces F2 of each optical fiber F after the movement based on the brightness of the image M7. In this case, the position recognition unit 20 can recognize the positions of the respective side surfaces F2 of the pair of optical fibers F in the X-axis direction. Thus, the positions of the side surfaces F2 of the pair of optical fibers F can be aligned, and therefore, high-precision core alignment of the pair of optical fibers F can be performed.

[0089] Next, with reference to Figure 13 and Figure 14 a fusion splicer of the modified example will be described. Figure 13 is a diagram for explaining a fusion method of a fusion splicer based on a modified example. Figure 14It is a diagram showing the image M24 of the surface measured by the above-described welding method. The position recognition unit 20 of the fusion splicer of the modification stores how many times the optical fiber F has been moved.

[0090] Figure 13 (1) thereof is a diagram showing the image M21 of the optical fiber F before movement. Figure 13 (2) thereof is a diagram showing the image M22 of the optical fiber F when it has been moved once in the Z-axis direction. Figure 13 (3) thereof is a diagram showing the image M23 of the optical fiber F when it has been moved twice in the Z-axis direction. As an example, when the size of one side of the pixel X1 is set to A (μm) (A is a positive real number), the moving distance (constant distance) of the optical fiber F each time is A / B (μm) (B is a natural number). In this case, when the optical fiber F is moved B times, the moving distance of the optical fiber F becomes the length of one side of a pixel X1. That is, the moving distance of the optical fiber F is 1 / B of the length of one side of the pixel X1. As an example, the value of A is 10 and the value of B is 3.

[0091] Hereinafter, the welding method of the fusion splicer based on the modification will be described. First, the optical fiber F is photographed by the microscope 15 to obtain the image M21 of the optical fiber F. The position recognition unit 20 recognizes the position of the optical fiber F in the image with the largest brightness difference between two pixels arranged along the Z-axis direction among the images M21, M22, and M23 for each pixel X1 arranged in the X-axis direction orthogonal to the Z-axis direction. The position recognition unit 20 recognizes that the brightness difference between the pixel X21 and the pixel X22 is the largest in the third pixel X1 group in the X-axis direction of the image M21, and recognizes the position between the pixel X21 and the pixel X22 as the position of the end face of the optical fiber F. The pixel X1 group represents a set of a plurality of pixels X1 arranged along the moving direction of the optical fiber F.

[0092] Next, in the same manner as above, the optical fiber F is moved a certain distance in the Z-axis direction and the optical fiber F is photographed by the microscope 15 to obtain the image M22 of the optical fiber F. The position recognition unit 20 recognizes that the brightness difference between the pixel X23 and the pixel X24 is the largest in the fifth pixel X1 group in the X-axis direction of the image M22, and recognizes the position between the pixel X23 and the pixel X24 as the position of the end face of the optical fiber F. The position recognition unit 20 recognizes that the brightness difference between the pixel X25 and the pixel X26 is the largest in the second pixel X1 group in the X-axis direction of the image M22, and recognizes the position between the pixel X25 and the pixel X26 as the position of the end face of the optical fiber F.

[0093] The optical fiber F is further moved a certain distance in the Z-axis direction, and the optical fiber F is photographed by the microscope 15 to obtain an image M23 of the optical fiber F. The position recognition unit 20 recognizes that the brightness difference between the pixel X27 and the pixel X28 is the largest in the fourth pixel X1 group in the X-axis direction of the image M23, and recognizes the position between the pixel X27 and the pixel X28 as the position of the end face of the optical fiber F. The position recognition unit 20 recognizes that the brightness difference between the pixel X29 and the pixel X30 is the largest in the first pixel X1 group in the X-axis direction of the image M23, and recognizes the position between the pixel X29 and the pixel X30 as the position of the end face of the optical fiber F.

[0094] The position recognition unit 20 recognizes the position of the end face of the optical fiber F before movement by subtracting the product of the number of movements of the optical fiber F and the certain distance from the position of the optical fiber F in the images M21, M22, and M23 with the largest brightness difference. The recognition of this position is performed for each pixel X1 arranged in the X-axis direction. Specifically, the position recognition unit 20 recognizes the position of the optical fiber F in the third pixel X1 group in the X-axis direction by subtracting 0 (0 (number of movements) × (A / B) (certain distance)) from the position of the optical fiber F in the image M21. That is, the position recognition unit 20 recognizes the position between the pixel X21 and the pixel X22 as the position of the end face of the optical fiber F before movement in the third pixel X1 group in the X-axis direction.

[0095] The position recognition unit 20 recognizes the position of the optical fiber F in the second and fifth pixels X1 in the X-axis direction by subtracting A / B (1 (number of movements) × (A / B) (certain distance)) from the position of the optical fiber F in the image M22. That is, the position recognition unit 20 recognizes the position that has moved 1 / B pixel amount in the opposite direction of the Z-axis direction from the position between the pixel X25 and the pixel X26 as the position of the end face of the optical fiber F in the second pixel X1 group in the X-axis direction. The result is expressed as Figure 14 of the image M24. The position recognition unit 20 recognizes the position that has moved 1 / B pixel amount in the opposite direction of the Z-axis direction from the position between the pixel X23 and the pixel X24 as the position of the end face of the optical fiber F in the fifth pixel X1 group in the X-axis direction.

[0096] The position recognition unit 20 recognizes the positions of the optical fiber F in the first and fourth pixels X1 in the X-axis direction by subtracting 2A / B (2 (number of movements) × (A / B) (constant distance)) from the position of the optical fiber F in the image M23. That is, the position recognition unit 20 recognizes, as the position of the end face of the optical fiber F, the position that has moved by a quantity of 2 / B in the direction opposite to the Z-axis direction from the position between the pixel X29 and the pixel X30 in the first pixel X1 group in the X-axis direction. The position recognition unit 20 recognizes, as the position of the end face of the optical fiber F, the position that has moved by a quantity of 2 / B in the direction opposite to the Z-axis direction from the position between the pixel X27 and the pixel X28 in the fourth pixel X1 group in the X-axis direction. As described above, by recognizing the position of the end face of the optical fiber F before movement for each pixel X1 group arranged in the X-axis direction by the position recognition unit 20, the shape of the end face of the optical fiber F can be grasped.

[0097] In the fusion splicer of the modified example, the position recognition unit 20 recognizes the position of the optical fiber F in the images M21, M22, and M23 where the brightness difference between two pixels X1 arranged along the movement direction is the largest, for each pixel X1 arranged in the direction (X-axis direction) orthogonal to the movement direction (Z-axis direction) of the optical fiber F. Since the position of the optical fiber F is recognized for each pixel X1 arranged in the direction orthogonal to the movement direction, the position of the end face can be measured in detail even if the shape of the end face of the optical fiber F is complex.

[0098] As described above, it may also be that the position recognition unit 20 stores the number of times the optical fiber F has moved a certain distance, or it may be that the position recognition unit 20 recognizes the position of the end face of the optical fiber F by subtracting the product of the number of movements of the optical fiber F and the constant distance from the position of the optical fiber F in the image with the largest brightness difference. In this case, the position of the end face of the optical fiber F before movement can be measured.

[0099] As described above, it may also be that the position recognition unit 20 recognizes the position of the end face of the optical fiber F for each pixel X1 arranged in the direction orthogonal to the movement direction. In this case, the position of the end face of the optical fiber F before movement can be measured in more detail.

[0100] Next, referring to Figure 15 and Figure 16 a fusion splicer of a further modified example will be described. Figure 15 is a diagram for explaining the fusion splicing method based on this fusion splicer. Figure 16 is a diagram of an image M34 of a surface measured by the above-described fusion splicing method. A part of the configuration of the fusion splicer of this modified example is the same as a part of the configuration of the fusion splicer of Figure 13 and Figure 14 Hereinafter, the description that overlaps with the fusion splicers of Figure 13 and Figure 14 will be appropriately omitted.

[0101] Figure 15 (1) is a diagram showing the image M31 of the optical fiber F before movement. Figure 15 (2) is a diagram showing the image M32 of the optical fiber F when it has been moved once in the X-axis direction. Figure 15 (3) is a diagram showing the image M33 of the optical fiber F when it has been moved twice in the X-axis direction. The position recognition unit 20 recognizes the position of the optical fiber F in the image M31, M32, or M33 where the brightness difference between two pixels arranged along the X-axis direction is the largest for each pixel X1 arranged in the Z-axis direction orthogonal to the X-axis direction.

[0102] The position recognition unit 20 recognizes that the brightness difference between pixel X31 and pixel X32 is the largest in the fourth pixel X1 group in the Z-axis direction of the image M31, and recognizes the position between pixel X31 and pixel X32 as the position of the side surface of the optical fiber F. The position recognition unit 20 recognizes that the brightness difference between pixel X33 and pixel X34 is the largest in the first pixel X1 group in the Z-axis direction of the image M31, and recognizes the position between pixel X33 and pixel X34 as the position of the side surface of the optical fiber F.

[0103] Next, the optical fiber F is moved a certain distance in the X-axis direction and the optical fiber F is photographed by the microscope 15 to obtain the image M32 of the optical fiber F. The position recognition unit 20 recognizes that the brightness difference between pixel X35 and pixel X36 is the largest in the second pixel X1 group in the Z-axis direction of the image M32, and recognizes the position between pixel X35 and pixel X36 as the position of the side surface of the optical fiber F.

[0104] The optical fiber F is further moved a certain distance in the X-axis direction, and the optical fiber F is photographed by the microscope 15 to obtain the image M33 of the optical fiber F. The position recognition unit 20 recognizes that the brightness difference between pixel X37 and pixel X38 is the largest in the third pixel X1 group in the Z-axis direction of the image M33, and recognizes the position between pixel X37 and pixel X38 as the position of the side surface of the optical fiber F.

[0105] The position recognition unit 20 recognizes the position of the optical fiber F in the fourth pixel X1 group in the Z-axis direction by subtracting 0 (0 (number of movement times) × (A / B) (certain distance)) from the position of the optical fiber F in the image M31. That is, the position recognition unit 20 recognizes the position between pixel X31 and pixel X32 as the position of the side surface of the optical fiber F before movement in the fourth pixel X1 group in the Z-axis direction. The position recognition unit 20 recognizes the position between pixel X33 and pixel X34 as the position of the side surface of the optical fiber F before movement in the first pixel X1 group in the Z-axis direction.

[0106] The position recognition unit 20 recognizes the position of the optical fiber F in the second pixel X1 in the Z-axis direction by subtracting A / B (1 (number of movements) × (A / B) (fixed distance)) from the position of the optical fiber F in the image M32. The result is represented as Figure 16 of the image M34. That is, the position recognition unit 20 recognizes, in the second pixel X1 group in the Z-axis direction, the position that has moved 1 / B pixel amount in the opposite direction of the X-axis direction from the position between the pixel X35 and the pixel X36 as the position of the side surface of the optical fiber F.

[0107] The position recognition unit 20 recognizes the position of the optical fiber F in the third pixel X1 in the Z-axis direction by subtracting 2A / B (2 (number of movements) × (A / B) (fixed distance)) from the position of the optical fiber F in the image M33. That is, the position recognition unit 20 recognizes, in the third pixel X1 group in the Z-axis direction, the position that has moved 2 / B amount in the opposite direction of the X-axis direction from the position between the pixel X37 and the pixel X38 as the position of the side surface of the optical fiber F. As described above, by the position recognition unit 20 recognizing the position of the side surface of the optical fiber F before movement for each pixel X1 group arranged in the Z-axis direction, the shape of the side surface of the optical fiber F can be grasped.

[0108] As described above, in the fusion splicer of this modification example, the position recognition unit 20 also recognizes the position of the optical fiber F in the image M31, M32, and M33, which has the largest brightness difference between two pixels X1 arranged along the movement direction, for each pixel X1 arranged in the direction (Z-axis direction) orthogonal to the movement direction (X-axis direction) of the optical fiber F. Thereby, even if the shape of the side surface of the optical fiber F is complex, the position of this side surface can be measured in detail. Therefore, the fusion splicer of this modification example can obtain the same effect as the Figure 13 and Figure 14 fusion splicer.

[0109] As described above, the embodiments and various modification examples of the fusion splicer and the fusion splicing method of the present disclosure have been described. However, the present invention is not limited to the above-described embodiments or modification examples, and can be appropriately changed within the scope of the gist described in the claims. The shape, size, number, material, and arrangement of each part of the fusion splicer are not limited to the above-described embodiments or modification examples, and can be appropriately changed within the scope of the above-described gist. The content and order of the steps of the fusion splicing method are not limited to the above-described embodiments or modification examples, and can be appropriately changed within the scope of the above-described gist. It can also be a fusion splicer or a fusion splicing method formed by combining multiple modes among the above-described embodiments and various modification examples.

[0110] For example, in the above-described embodiment, an example was described in which the driving unit 14 is a stepping motor and the amount of movement of the optical fiber F each time based on the driving unit 14, i.e., a fixed distance, is 1 μm or more and less than 10 μm. Then, an example was described in which the microscope 15 photographs the optical fiber F every time the optical fiber F moves a fixed distance. For example, the microscope 15 may photograph the optical fiber F each time the driving unit 14 moves the optical fiber F by one pulse, or the microscope 15 may photograph the optical fiber F each time the driving unit 14 moves the optical fiber F by two pulses. Thus, the frequency at which the microscope 15 photographs the optical fiber F can be appropriately changed. However, for higher-precision position recognition, it is ideal that the microscope 15 photographs the optical fiber F each time the driving unit 14 moves the optical fiber F by one pulse. In addition, the driving unit may be a component other than a stepping motor, and the type of the driving unit is not particularly limited.

[0111] Explanation of Reference Numerals

[0112] 1: Fusion splicer;

[0113] 2: Housing;

[0114] 3: Fusion section;

[0115] 3a: Optical fiber positioning section;

[0116] 3b: Electrode bar;

[0117] 3c: Optical fiber holder;

[0118] 4: Heater;

[0119] 5: Monitor;

[0120] 6: Windshield;

[0121] 7: Power switch;

[0122] 8: Connection start switch;

[0123] 11: Table;

[0124] 12: Main surface;

[0125] 13: V-groove;

[0126] 14: Driving unit;

[0127] 15: Microscope;

[0128] 16: Imaging element;

[0129] 17: Image processing unit;

[0130] 20: Position recognition unit;

[0131] F: Optical fiber;

[0132] F1: End face;

[0133] F2: Side face;

[0134] L: Imaginary straight line;

[0135] M1, M2, M3, M4, M5, M6, M7, M11, M12, M13, M14, M15, M21, M22, M23, M24, M31, M32, M33, M34: Images;

[0136] P: Position;

[0137] X, X1, X2, X3, X11, X12, X13, X14, X15, X21, X22, X23, X24, X25, X26, X27, X28, X29, X30, X31, X32, X33, X34, X35, X36, X37, X38: Pixels;

[0138] Y, Z: Reference positions.

Claims

1. A fusion splicer, comprising: a stage for placing an optical fiber; a driving unit for moving the stage; a microscope for photographing the optical fiber and outputting the brightness of the image obtained by photographing for each pixel; and a position recognition unit for recognizing the position of the surface of the optical fiber based on the brightness of each pixel output by the microscope, the driving unit moves the optical fiber a certain distance each time, the certain distance is shorter than the pixel size of the pixel, whenever the driving unit moves the optical fiber by the certain distance, the microscope photographs the optical fiber, the position recognition unit recognizes the position of the surface of the optical fiber after being moved by the driving unit based on the brightness of a plurality of the images obtained by the microscope.

2. The fusion splicer according to claim 1, wherein the position recognition unit recognizes the position of the surface in the image among the plurality of images where the position of the surface of the optical fiber is closest to one side of the pixel as the reference position.

3. The fusion splicer according to claim 2, wherein the position recognition unit recognizes the position of the optical fiber in the image with the largest brightness difference between two pixels arranged along the moving direction of the optical fiber among the plurality of images as the reference position.

4. The fusion splicer according to claim 2 or 3, wherein the position recognition unit stores the moving distance of the optical fiber from the reference position, and adds the moving distance of the optical fiber from the reference position to the reference position to recognize the position of the surface.

5. The fusion splicer according to claim 4, wherein the position recognition unit stores how many times the optical fiber has moved the certain distance from the reference position, and adds the product of the number of times the optical fiber has moved from the reference position and the certain distance as the moving distance to the reference position to recognize the position of the surface.

6. The fusion splicer according to claim 1, wherein the position recognition unit recognizes the position of the optical fiber in the image with the largest brightness difference between two pixels arranged along the moving direction among the plurality of images for each pixel arranged in a direction orthogonal to the moving direction of the optical fiber.

7. The fusion splicer according to claim 6, wherein the position recognition unit stores how many times the optical fiber has moved the certain distance, and recognizes the position of the surface by subtracting the product of the number of times the optical fiber has moved and the certain distance from the position of the optical fiber in the image with the largest brightness difference.

8. The fusion splicer according to claim 6 or 7, wherein the position recognition unit recognizes the position of the surface for each pixel arranged in a direction orthogonal to the moving direction.

9. The fusion splicer according to any one of claims 1 to 8, wherein the driving unit moves the optical fiber along the long dimension direction of the optical fiber.

10. The fusion splicer according to any one of claims 1 to 8, wherein the driving unit moves the optical fiber along a direction orthogonal to the long dimension direction of the optical fiber.

11. The fusion splicer according to any one of claims 1 to 10, wherein The certain distance is less than or equal to one half of the pixel size.

12. The fusion splicer according to any one of claims 1 to 11, wherein the surface is the end face of the optical fiber at one end in the long dimension direction of the optical fiber.

13. The fusion splicer according to any one of claims 1 to 11, wherein the surface is the side face of the optical fiber extending along the long dimension direction of the optical fiber.

14. The fusion splicer according to any one of claims 1 to 13, wherein the microscope has: an imaging element that images the optical fiber; and an image processing unit that processes an image of the optical fiber captured by the imaging element, and the image processing unit outputs the brightness of the image for each pixel.

15. The fusion splicer according to claim 14, wherein the image processing unit calculates a brightness difference between two pixels arranged along the moving direction of the optical fiber, and the position recognition unit stores the brightness difference calculated by the image processing unit.

16. The fusion splicer according to any one of claims 1 to 15, wherein the fusion splicer is a multi-core fusion splicer that fuses a plurality of the optical fibers together.

17. The fusion splicer according to any one of claims 1 to 16, wherein the position recognition unit stores an image captured by the microscope and identifies the position of the optical fiber based on the brightness of each pixel output.

18. The fusion splicer according to any one of claims 1 to 17, wherein the position recognition unit identifies the position of the surface of the optical fiber as the position of the pixel between the pixel with the highest brightness and the pixel with the lowest brightness among the plurality of pixels.

19. A fusion splicing method, comprising the following steps: Moving a stage on which an optical fiber is placed; Imaging the optical fiber; Outputting the brightness of an image obtained by the imaging step for each pixel; and Identifying the position of the surface of the optical fiber based on the brightness of each pixel, In the moving step, moving the optical fiber by a certain distance each time, wherein the certain distance is shorter than the pixel size of the pixel, In the imaging step, imaging the optical fiber each time the optical fiber moves the certain distance, In the position identifying step, identifying the position of the surface of the moved optical fiber based on the plurality of brightnesses of the plurality of images.

Images